Abstract: A radio frequency (RF) communications system may include a first RF node that transmits data, including a new frequency of operation, and a sequence of pilot symbols spread with a complex spreading code sequence. A second RF node may receive an incoming signal from the first RF node and perform despreading for N sample offset delays to generate N despreading sequences for the sequence of pilot symbols. The second RF node may perform a cross-correlation to select a desired despreading sequence from the N despreading sequences, determine a phase offset and timing offset, process the incoming signal based upon the desired despreading sequence, phase offset and timing offset, and switch to the new frequency of operation.

Abstract: Communicating using spread spectrum. A legacy RF signal is intercepted from a legacy radio. Spread spectrum processing is performed on the legacy RF signal to create a spread signal. The spread signal is transmitted to a receiver, whereafter the spread signal is de-spread to recover the legacy RF signal.

Abstract: Communicating using spread spectrum. A legacy RF signal is intercepted from a legacy radio. spread spectrum processing is performed on the legacy RF signal to create a spread signal. The spread signal is transmitted to a receiver, whereafter the spread signal is de-spread to recover the legacy RF signal.

Abstract: Transmitting a signal from a transmitter. A method includes identifying a threshold spectral flux density for a given physical location. The method further includes, as a result of identifying the threshold spectral flux density, transmitting a signal at a power level causing the signal to be below the spectral flux density at the given physical location, the signal being transmitted at a data rate. The method further includes receiving feedback from a receiver indicating the signal-to-noise ratio of the signal at the receiver. The method further includes adjusting the data rate of the signal based on the feedback. The method further includes continuing transmitting the signal at the adjusted data rate and power level.

Abstract: Transmitting a signal from a transmitter. A method includes identifying a threshold spectral flux density for a given physical location. The method further includes, as a result of identifying the threshold spectral flux density, transmitting a signal at a power level causing the signal to be below the spectral flux density at the given physical location, the signal being transmitted at a data rate. The method further includes receiving feedback from a receiver indicating the signal-to-noise ratio of the signal at the receiver. The method further includes adjusting the data rate of the signal based on the feedback. The method further includes continuing transmitting the signal at the adjusted data rate and power level.